package com.hmdp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

@Component
public class RedisIdWorker {
    /**
     * 开始时间戳
     */
    private static final long BEGIN_TIMESTAMP = 1640995200L;
    /**
     * 序列号的位数
     */
    private static final int COUNT_BITS = 32;

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    public Long nextId(String key){
        // 生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowEpochSecond = now.toEpochSecond(ZoneOffset.UTC);
        long timeStamp = nowEpochSecond - BEGIN_TIMESTAMP;
        // 生成序列号
        String data = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        long count = stringRedisTemplate.opsForValue().increment("icr:"+key+":"+data);

        // 返回唯一id
        return timeStamp<<COUNT_BITS|count;
    }
}
